This invention relates to poles for holding wires and cables, such as telephone, cable television, power or other types of lines in the air and, more particularly, to devices to aid in the climbing of such poles, including pole steps that are permanently mounted to poles, and step mounts that are mounted to poles which provide attachment points for temporary steps, accessories or other equipment.
Various types of poles, such as wooden, steel, concrete or fiberglass poles have been used in the past for holding overhead lines. In order to climb these poles, spiked climbing boots are used. However, frequent climbing of the poles in this manner cause damage to the poles. Steps are therefore often installed for poles that may require frequent climbing, eliminating the need to use spiked climbing boots. While permanent steps are often attached to poles, there are some instances where such steps are not desirable. Permanently installed steps that extend to the bottom of the pole may create the problem of unauthorized pole climbing. To address this problem, temporary pole steps are sometimes used for approximately the first ten (10) feet of pole height. These temporary steps are typically carried by the person climbing the pole and are installed on mounts which are permanently attached to the pole.
The most common permanent step design is a ⅝ inch diameter steel bolt, 9-10 inches long, with a coarse lag screw thread on one end, and a turned up foot guard on the other end. The step is hammered or screwed 3-4 inches into the wooden pole, leaving approximately 6 inches protruding from the face of the pole, with the foot guard pointing upwards.
There are a number of other permanent step bolt designs for use with other types of poles and towers. For instance, a common practice in providing for easy climbing on steel lattice towers is to drill a hole in the main steel angle and install a ⅝ inch diameter bolt with two nuts and a lockwasher. The nuts and lockwasher securely fasten the bolt to the steel angle of the structure leg. A common practice with steel poles, on the other hand, is to weld a nut to the outer surface of the pole and then screw the step bolt into the nut. Another method is to weld a special bracket to the steel pole which allows attachment of climbing ladders. In the case of a concrete pole, threaded inserts for pole steps are cast into the pole at the time of fabrication. One method that can be used with wood, steel or concrete poles is to drill a hole through the entire pole and install a bolt, long enough to fit across the entire diameter of the pole. This method, however, is extremely expensive.
Typically, the temporary step mount assembly for a traditional wooden pole consists of a large nail with a specially shaped head. The nail is pounded into the pole leaving the head exposed approximately xc2xdxe2x80x3 from the face of the pole. A temporary step may then be slid onto the head of the nail.
With the availability of wooden poles declining, and their cost rising, a newer entrant into the overhead power distribution and communications industry is the hollow fiberglass pole. With a fiberglass pole, none of the traditional permanent or temporary pole steps are practical because they are either not of a suitable design or are too costly. The wall thickness and characteristics of the fiberglass preclude the use of a screwed-in pole step. Use of a step bolt with inner and outer nuts, as is used on lattice towers, is impossible because the inside of the pole is not accessible. Attaching a nut to the surface of a pole, or embedding it in the wall of the pole is not feasible either. Finally, installing a bolt through the entire diameter of the pole may work, but is not an economical solution.
With the increasing use of hollow poles, such as fiberglass, steel or concrete poles, as a replacement for wooden poles, different attachment methods became necessary for mounting permanent pole steps and/or step mounts for temporary steps. The most commonly used method today, for example, for a fiberglass pole, is a xc2xdxe2x80x3 diameter xe2x80x9cLxe2x80x9d shaped bolt that is inserted into a ⅝xe2x80x3 diameter hole drilled in the wall of the pole. Once the xe2x80x9cLxe2x80x9d shaped bolt is inserted into the pole, a backing plate, spacing washer, lockwasher and nut are installed over the protruding leg of the xe2x80x9cLxe2x80x9d bolt to keep the bolt locked in place. However, as the nut is tightened on the L-shaped bolt, the bolt tends to pull out from the hole, and cause the horizontal leg of the bolt to angle upwards (and consequently, causes the vertical leg to pull away from the inside wall of the pole). Further, the L-shaped bolts may rotate, which is dangerous whether the bolt is itself a step, or the bolt is a mount for a temporary step. Another drawback of this method is that the bolt typically extends approximately 1xc2xdxe2x80x3 from the backing plate, and unauthorized persons may attempt to climb the pole using these small protrusions as steps. In addition, some localities prohibit the use of a step mount with a protrusion of such size.
It is therefore desirable to have a permanent pole step and an attachment mount design for hollow poles, such as fiberglass, steel and concrete poles, or any pole with a hollow space or cavity inside, that is practical to use, is economical, provides a substantially horizontal step or mounting surface, does not rotate, and is effective in keeping unauthorized persons from climbing the poles.
The present invention therefore provides an apparatus which aids in the climbing of hollow poles, by providing permanent steps, or by providing attachment points for temporary steps, accessories and other equipment to hollow poles. The invention may be practiced in a variety of embodiments, including permanent steps for attaching to hollow poles, as well as mounts that attach permanently to hollow poles allowing the subsequent attachment of removable temporary steps, or other accessories or equipment. The present invention therefore provides a permanent pole step and/or attachment mount for removable steps, accessories or equipment for hollow poles that is practical and economical to use, and that provides a substantially horizontal step or mounting surface that does not rotate and that extends only a limited distance from the hollow pole.
A first embodiment of the present invention is a permanent step for a hollow pole, comprising essentially of a support member and a mating plate. A portion of the support member is inserted into a mounting hole of the pole and the remaining portion of the support member protrudes out of the hole to create a stepping surface. The plate has a hole which receives the support member, and a tongue which mates with the support member to secure the support member.
A second embodiment of the present invention is an attachment mount for attaching temporary steps, equipment or accessories to a hollow pole, comprised essentially of a support member, a mating plate and a guide washer. A portion of the support member is inserted into a mounting hole of the pole, and the remaining portion protrudes out of the hole. The plate has a hole which receives the support member, and a tongue which mates with the support member to secure it in place. The guide washer substantially abuts the plate, and provides a gap where between the plate and the washer where temporary steps, equipment or other accessories are attached.
A third embodiment of the present invention is an attachment mount for a hollow pole comprising essentially of a support member, a plate, and a collapsing cage. The cage is inserted through a hole in the plate, and the support member is inserted through the plate and into the cage. The assembly is partially inserted into the hollow pole up to the plate, and the cage is collapsed to form a truss against the interior wall of the pole. At the proper torque, the head of the support member shears off, leaving only a small protrusion beyond the plate, with a button-type head for attachment of a temporary step, equipment or other accessories.